Traditional knowledge of plants used in hunting and fishing practices among Baka hunter-gatherers of eastern Cameroon

Background Baka hunter-gatherers have a well-developed traditional knowledge of using plants for a variety of purposes including hunting and fishing. However, comprehensive documentation on the use of plants for hunting and fishing in eastern Cameroon is still lacking. Method This study aimed at recording plants used for hunting and fishing practices, using focus group discussion, interviews and field surveys with 165 Baka members (90 men and 75 women) of different age groups in 6 villages. Results The most frequent techniques used for hunting and fishing are the use of animal traps, fishing lines, dam fishing, hunting with dogs and spear hunting. We recorded a total of 176 plant species used in various hunting practices, the most frequently cited one being Zanthoxylum gilletii (De Wild.) P.G.Waterman, Greenwayodendron suaveolens (Engl. & Diels) Verdc., Microcos coriacea (Mast.) Burret, Calamus deërratus G.Mann & H.Wendl. and Drypetes sp. These plants are used for a variety of purposes, most frequently as hunting luck, psychoactive for improving the dog’s scent and capacity for hunting, materials for traps, and remedies for attracting animals and for making the hunter courageous. Conclusion Plants used for hunting purposes here are embedded in a complex ecological and cultural context based on morphological characteristics, plant properties and local beliefs. This study provides a preliminary report and leaves room for further investigations to improve the documentation of the traditional knowledge systems of the studied community.


Introduction
Baka hunter-gatherers heavily depend on wild forest resources (plants, animals) to meet their subsistence and cash income needs. Some studies in several sites have shown that they have a well-developed traditional knowledge of using plants for a variety of purposes including not only for direct material uses as food, medicines, craft and building materials hunting, and fishing but also for religious practices [1][2][3][4][5][6][7][8]. Hunting and fishing by the Baka hunter-gatherers are very important activities from ecological, social and cultural points of view, and bushmeat is among their most preferred food [9]. Although they are traditionally spear hunters [10], they have experienced through time a diversity of techniques and methods for hunting and fishing including snare hunting for medium-sized mammals, mouse traps, use of fire to smoke prey animals out of burrows, dam fishing, fishpoisoning, hunting with dogs, machetes ad catapults, as well as hunting with shotguns, from sedentary or migratory camps, etc. [11][12][13][14][15][16].
Various studies have also reported the use of plants and plant products for fishing and hunting. Previous studies reported up to 325 fish poison species used in tropical Africa, the most frequently used being Tephrosia vogelii Hook.f., Mundulea sericea (Willd.) A.Chev., Euphorbia tirucalli L., Gnidia kraussiana Meisn., Adenia lobata (Jacq.) Engl and Balanites aegyptiaca (L.) Delile [17]. Many of these species were also reported as used for preparing arrow poisons and traditional medicine. Hunting of the Baka people not only involves the direct use of poisonous plants and weapons such as gun, nets, spear, bows and traps. It also involves the use of dogs, especially the use of plant medicine for improving the dogs' hunting ability, and for a variety of hunting rituals. While ethnobotanical knowledge of the Baka hunter-gatherers has been investigated by several authors, comprehensive documentation on the use of plants for hunting is still lacking.
In the face of the recent shift in the Bakas' subsistence activity from hunting and gathering to farming, the change in their lifestyle and the development of education support projects, anthropologists and activists working for indigenous issues have expressed their concern about the risks of degradation of traditional ecological knowledge among Baka hunter-gatherers. Indeed, it seems that fewer Baka people are now involved in traditional hunting and gathering activities. [18] emphasize that the creation of national park and forest concessions are the factors that limited the access of Baka members to hunting. However, previous studies show that a number of socio-economic variables influence traditional ecological knowledge among indigenous communities. These variables include age, gender, consumerism, occupation, and psychosocial variables [19][20][21][22][23][24].
.These studies, depending on the scale of analysis, pointed out significant differences on national and continental levels. On the global level, however, no significant difference was reported between women and men. Concerning the age variable, several studies reveal that youth are reported to show a greater diversity of plant knowledge [22,25]. The present research aims at documenting the diverse uses of plants in hunting practices among the Baka community members in Eastern Cameroon. We hypothesize that the ethnobotanical hunting knowledge of Baka huntergatherers is rich and varies with age and gender.

Study site
The study was conducted in six villages along the road from Abong Mbang to Messok: Bitsomo (3.14785 N, 13.65072E), Nomedjo (3.34169 N, 13.59048 E), Adjela Baka (3.15397 N, 13.61487 E), Sissok (3.147857 N, 13.65072E), Payo (3.14569 N, 13.70801E) and Bosquet (3.12655 N,13.88085E) (Fig. 1). These villages are located in the Lomie council, in the Haut Nyong Division of, East Cameroon Region. The total population of the council is approximately 19,000 inhabitants [26]. The local population consists of four main ethnic groups: Zime, Kako, Ndjeme and the Baka, living along the side road and speaking the Baka language. They are mainly Christians and Muslims [26]. The predominant forms of their livelihoods are shifting cultivation, cacao garden cultivation, hunting, fishing and gathering. Various, NTFPs (Non-Timber Forest Products) are collected and sold.
The vegetation of the area is part of the camerounocongolian forest consisting of a semi-deciduous forest comprised of a majority of Malvaceae and Ulmaceae [27,28].
The area is subject to a Guinean equatorial climate with four seasons divided as follows: a long dry season from December to mid-March; a short rainy season from mid-March to June; a short dry season in July-August; a long rainy season from August to November. The mean annual rainfall varies from 1500 to 2000 mm, with an average temperature of 24 °C.

Sampling and data collection approach
The ethnobotanical approach applied in this study used focal group discussion, interviews and field surveys in the forest, with 165 Baka members from the six study villages (Table 1). These villages were chosen based on the presence of an important Baka community and the prior consent given by the Chief of the village. Respondents in each village were chosen at random, based on their willingness to participate in the research.
During the focal group discussion, it was clearly explained to the community members that the objective of the study was to record the plants used for hunting and fishing practices according to age and gender to obtain their prior informed oral consent. Individual interviews were conducted to gather information on their experience of using plants in hunting and fishing practices.
Respondents were asked about their age, gender, hunting methods employed, local names of plants used in hunting activities, parts used, and usage. To obtain effective participation of respondents, interviews were conducted in the local language with the help of local translators.
The interviews were followed by fieldwork in the forest, which gave an opportunity for more discussions with respondents. This was also an opportunity to observe and gather information on the plant species free-listed by respondents. Plants named during the interviews were identified in situ in the field using available floral reference literature [29][30][31][32]. Plants that were spontaneously found when walking in the forest were also considered and information on their uses was recorded. For each unidentified plant species cited during the interview in the village, a specimen was collected, pressed and dried, and their identification was confirmed at the Cameroon National Herbarium in Yaoundé (YA). The voucher specimen was kept at Millennium Ecological Museum Herbarium and at the National Herbarium in Yaounde. Some of the plants listed by respondents during the interviews were not found during the forest walks and remained unidentified. These plants referred to as ethnospecies in the present study also included those that were known in their uses category, but the respondent was not able to remember the vernacular name.

Data analysis
Simple descriptive statistics were applied to represent and list the number and percentage of species of plants and plant parts used. The floral list of plants cited by respondents was grouped based on their age and gender.  The frequency of citation (F) for each hunting and fishing technique and species was calculated. It corresponds to the ratio between the number of respondents (n) having cited the technique or species and the total number of respondents (N): The magnitude of plant knowledge among each group (represented by the total number of plants cited) was used as a measurement of ethnobotanical knowledge. NNESS similarity index between the lists of plant species cited by each group was used as means of comparison.
This index is used to compare with minimum bias the degree of similarity of two samples (i and j) on the basis of an identical data size k randomly selected from each sample. The similarity between the two samples (i and j) is expressed by the Morisita-Horn index and by its generalization, the NNESS index, which is a variant of the NESS index [33]. The formula is given below and was computed using the software BiodivR 1.0 [34].
where ESS ij/k is the expected number of species shared for random draws of k specimens from sample i and k specimens from sample j. The more the value is close to 1, the more the pairs of species lists compared are floristically similar. Values above 0.5 can denote a great number of similar species shared by the two lists.

Hunting techniques
The results showed a total of 13 hunting techniques used by the Baka hunter-gatherers. The most frequently used techniques are animal traps, fishing lines, dam fishing, hunting with dogs and spear hunting (Fig. 2).

Plant species used in hunting practices
A total of 176 plant species were recorded as used in the various hunting practices from the interviews with the Baka. The cumulative diagram of plant species recorded showed that the sampling size was adequate, as new species were hardly added despite the increase in the number of persons interviewed (Fig. 3).
The  Table 2). While the rattan species identified during the survey was Calamus deerratus, respondents insisted that all rattan species can be used as well.
These plants were used for a variety of purposes including materials for making traps, baskets for transportation, arrow poison, fish poison, etc. (Fig. 4). Others were used in ritual practices aimed at becoming invisible to dangerous animals, attracting animals, or to have luck when going out for a hunting expedition. Others were used directly by the hunter to be courageous or . This might be partly explained by the larger size of this group interviewed. The highest ratio of plant citation per respondent is recorded in the age group 50-60 years where a total of 14 respondents cited as many as 73 species, with a ratio of 5.21 per respondent ( Table 3). The value of the NNESS similarity index between lists of plants cited by men and women was 0.68, indicating a certain degree of commonality between the two groups.
The plants listed by aged members (+ 60 years) were significantly different from those of other age groups, as this is shown by the NNESS values of 0.39, which means the most-aged groups cited fewer common species (Table 4).
The group of 10-20 years old and that of above 60 years shared only 25 common species. Of the 89 species cited by younger groups, 53 were not cited by the group of above 60 years. Among those non-common species, the

Discussion
In the study villages, the importance of plants in hunting and fishing practices is well established. The plant species recorded as used in hunting practices are taxonomically quite diverse. Some have been cited more frequently than others. A previous botanical survey in this peripheral site of the Dja biosphere reserve has reported wider distribution and abundance of these species in the study area [35]. Given this availability, the Baka peoples in the study villages may therefore preferentially use the plants that are readily available in their neighbourhood for hunting purposes. Hunting and fishing practices recorded in the studied villages are in line with those previously reported by other researchers [12,[36][37][38][39]. Some of the species recorded as used in fishing and hunting practices have been described to have similar uses in the previous ethnobotanical literature in central Africa [2,8]. The use            [39,40] and [4]. Some of the recorded plants like Drypetes spp. and Greenwayodendron suaveolens have also been reported as used for making spears or snares by Baka hunter-gatherers in Cameroon [15].  [39][40][41]. Natural poisons derived directly from plants have been used in fishing for millennia [42,43], poisonous ingredients are pounded and thrown into a pool or dammed sections of a small river. After a time, which varies according to conditions the fish begin to rise to the surface of the water and can readily be taken by hand [17]. Several studies have shown that these poisons have no effect on human health, humans can digest it relatively safely [17,44]. Although the consumption of preys killed with the natural poison has no effect on human health, [45] recorded an anaesthetic effect on limbs and roughness of skin of people who wade into streams to collect fish poisoned with Tephrosia vogelii Hook.f. These considerations should definitely be taken into account in the spread of these practices. The major problem in using fishing poisons is the massive destruction of aquatic organisms. Natural fish poisons paralyse or kill fish; sometimes, they kill other aquatic organisms; therefore, this practice has been banned in many contexts due to the ecological damage it can cause [17,46]. Results of this study show that there is an uneven distribution of ethnobotanical knowledge for hunting within studied communities. Although the ratio of plant citation per respondent was higher among aged groups, similarity analysis shows that younger respondents cited a larger number of plant species used for hunting and fishing and that they named many plants that were not cited by the elders. These observations are contrary to those of [47] who reported that only adults can master hunting or medicinal plant knowledge. For instance, ethnobotanical knowledge acquisition process among the studied community involves plural channels and sources. It is acquired through contact with the people with different background, such as family members, schoolmates and neighbours of other ethnic groups, associated with their socialization process. Younger members of the community engage in a variety of game and subsistence-related activities. The Baka living on the periphery of the Dja biosphere are sedentary along the roads, so the young Baka interact with many other youths including Bantus of the similar age, and through this process of social contacts, there is a dynamic of recompositing of their original traditional knowledge acquired from their family members. In these dynamics, they accumulate their  own ethnobotanical knowledge that extends beyond the scope of knowledge acquired within a narrow range of their own family. This observation is consistent with previous findings by [20] on the Baka in the same region of East Cameroon. Moreover, it is clearly established that traditional ecological knowledge transmission most often occurs between older and younger generations, or vertical instruction; it can also occur through more horizontal interactions between peers and through oblique transmission from non-familial mentors [48]. These different knowledge acquisition pathways were qualified as "multiple-stage learning process" by [49,50]. From the similarity indices among the plant lists of different groups of respondents, it is shown that 68% of plant species recorded are shared between men and women. This commonality, however, masks finer gender differences. The social organization of the hunting activities involves both men and women who share the responsibilities. Although some of the hunting activities are performed by men, many of the rituals during which plants are used are performed by women and particularly virgin girls. In fact, from the discussion with respondents, it was revealed that according to the traditional beliefs within Baka society, the prayers and words sent to the ancestors to ask for luck require that the person sending the prayers be "pure". For instance, virgin girls in Baka society are a symbol of good moral behaviour and conduct and thus of purity, as they have not yet engaged in sexual relationships considered as a sin that defiles the body of the person. Hence, they believe that their ancestors would be happy, answering to the will of virgin girls than that of any other person.
There are cases where women, especially elder members, play a key role in the transmission of ethnobotanical knowledge for hunting to men.
In such a context, ethnobotanical hunting knowledge acquisition within the studied communities might involve several individual and collective factors associated with their socialization process.

Conclusion
This study was conducted to document the traditional knowledge of plants used in hunting practices among the Baka community members in Eastern Cameroon. Results showed a taxonomic list of 176 species used by the studied populations. In the practice of hunting or fishing, these plants are used for a variety of purposes including as materials for making traps or baskets for transportation, arrow or fish poison, traditional medicine used by the hunter to be courageous or by the dogs to improve their scent and ability for hunting, materials for ritual practices performed to become invisible to dangerous animals, attract animals, to chase away dangerous animals or to have luck when going out for a hunting expedition.
Although female Baka are traditionally more active in fishing, they are knowledgeable of plants used for hunting as well. The ethnobotanical knowledge of using plants for hunting did not vary significantly with gender, but showed some variation among age groups, with younger members citing more plants than the elder. For further investigations, a comparative study with neighbouring Bantu communities will be important to understand the dynamics of inter-community knowledge exchange.